package org.xxpay.pay.channel.guanghui.utils;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;


public class Base64Util
{

    /**
     *
     * @Title: decryptBASE64
     * @Description: TODO(Base64解密方法)
     * @param @param key
     * @param @return
     * @param @throws Exception    设定文件
     * @return byte[]    返回类型
     * @throws
     */
    public static byte[] decryptBASE64(String key) throws Exception {
        return (new BASE64Decoder()).decodeBuffer(key);
    }

    /**
     *
     * @Title: encryptBASE64
     * @Description: TODO(Base64加密方法)
     * @param @param key
     * @param @return
     * @param @throws Exception    设定文件
     * @return String    返回类型
     * @throws
     */
    public static String encryptBASE64(byte[] key) throws Exception {
        return (new BASE64Encoder()).encodeBuffer(key);
    }

    /**
     * 将原始数据编码为base64编码
     */
    static public byte[] encode(byte[] data) {
        byte[] out = new byte[((data.length + 2) / 3) * 4];
        for (int i = 0, index = 0; i < data.length; i += 3, index += 4)
        {
            boolean quad = false;
            boolean trip = false;
            int val = (0xFF & (int) data[i]);
            val <<= 8;
            if ((i + 1) < data.length)
            {
                val |= (0xFF & (int) data[i + 1]);
                trip = true;
            }
            val <<= 8;
            if ((i + 2) < data.length)
            {
                val |= (0xFF & (int) data[i + 2]);
                quad = true;
            }
            out[index + 3] = alphabet[(quad ? (val & 0x3F) : 64)];
            val >>= 6;
            out[index + 2] = alphabet[(trip ? (val & 0x3F) : 64)];
            val >>= 6;
            out[index + 1] = alphabet[val & 0x3F];
            val >>= 6;
            out[index + 0] = alphabet[val & 0x3F];
        }
        return out;
    }

    static public byte[] encodeSafe(byte[] data) {
        byte[] out = new byte[((data.length + 2) / 3) * 4];
        for (int i = 0, index = 0; i < data.length; i += 3, index += 4)
        {
            boolean quad = false;
            boolean trip = false;
            int val = (0xFF & (int) data[i]);
            val <<= 8;
            if ((i + 1) < data.length)
            {
                val |= (0xFF & (int) data[i + 1]);
                trip = true;
            }
            val <<= 8;
            if ((i + 2) < data.length)
            {
                val |= (0xFF & (int) data[i + 2]);
                quad = true;
            }
            out[index + 3] = alphabet_safe[(quad ? (val & 0x3F) : 64)];
            val >>= 6;
            out[index + 2] = alphabet_safe[(trip ? (val & 0x3F) : 64)];
            val >>= 6;
            out[index + 1] = alphabet_safe[val & 0x3F];
            val >>= 6;
            out[index + 0] = alphabet_safe[val & 0x3F];
        }
        return out;
    }

    /**
     　　* 将base64编码的数据解码成原始数据
     　　*/
    static public byte[] decode(byte[] data) {
        int len = ((data.length + 3) / 4) * 3;
        if (data.length > 0 && data[data.length - 1] == '=') --len;
        if (data.length > 1 && data[data.length - 2] == '=') --len;
        byte[] out = new byte[len];
        int shift = 0;
        int accum = 0;
        int index = 0;
        for (int ix = 0; ix < data.length; ix++)
        {
            int ch = data[ix] & 0xFF;

            //+/  -_
            if (ch == '-') ch = '+';
            else if (ch == '_') ch = '/';

            int value = codes[ch];
            if (value >= 0)
            {
                accum <<= 6;
                shift += 6;
                accum |= value;
                if (shift >= 8)
                {
                    shift -= 8;
                    out[index++] = (byte) ((accum >> shift) & 0xff);
                }
            }
        }
        if (index != out.length) return null;
        //throw new Exception("miscalculated data length!");
        //throw new Error("miscalculated data length!");
        return out;
    }

    static private byte[] alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=".getBytes();
    static private byte[] alphabet_safe = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_=".getBytes();

    static private byte[] codes = new byte[256];
    static
    {
        for (int i = 0; i < 256; i++)
            codes[i] = -1;
        for (int i = 'A'; i <= 'Z'; i++)
            codes[i] = (byte) (i - 'A');
        for (int i = 'a'; i <= 'z'; i++)
            codes[i] = (byte) (26 + i - 'a');
        for (int i = '0'; i <= '9'; i++)
            codes[i] = (byte) (52 + i - '0');
        codes['+'] = 62;
        codes['/'] = 63;
    }

    public static void main(String[] args) throws Exception
    {
        String data = Base64Util.encryptBASE64("test".getBytes());
        System.out.println("加密前："+data);

        byte[] byteArray = Base64Util.decryptBASE64(data);
        System.out.println("解密后："+new String(byteArray));
    }
}